The overall goal of this SBIR Phase II application is to develop a family of microcarrier products that have a synthetic or recombinant collagen peptide bound to the bead surface. These microcarrier products would replace current microcarriers that have porcine collagen (i.e., gelatin) as part of the attachment surface. The synthetic collagen peptide-coated microcarriers would be an ideal replacement for existing products in animal product-free manufacturing protocols. Currently, three collagen-coated microcarriers, (a collagen-coated dextran bead [Cytodex 3] manufactured offshore and SoloHill's two gelatin-coated microcarriers) are the most extensively used microcarrier substrates in the industrial scale production of anchorage-dependent cells. As manufacturers of viral vaccines and other biologicals move toward complete animal product-free manufacturing conditions, a substrate containing collagen or gelatin will not be acceptable. Microcarriers with a synthetic collagen peptide - coated surface would provide an ideal replacement. The Phase II studies described here follow directly from the successes achieved in Phase I. The Phase II work plan is divided into three overall specific aims. Specific Aim I. To develop a microcarrier that has a synthetic collagen peptide on its surface. This microcarrier would be an animal product-free equivalent of (and in some applications a replacement for) the SoloHill gelatin-coated microcarriers. Specific Aim II. To develop a dextran microcarrier that has a synthetic collagen peptide on its surface. This microcarrier would be an animal product-free equivalent of (and a replacement for) the collagen-linked dextran microcarriers now manufactured and sold by a foreign competitor. Specific Aim IIl. To investigate the utility of additional microcarrier synthetic surface coatings as replacements of current products with porcine gelatin on the surface. Examples are modifications to the current synthetic collagen peptide and recombinant human collagen and gelatins.